The present invention relates to an air purifying apparatus that destroys microorganisms and removes odors and other impurities from the air.
Today, a large number of pollutants can be found in the air and water. Among the various harmful air pollutants that exist in the air that people breath are pollen, lung damaging dust, smoke and bacteria. Other pollutants include various organic vapors and toxic gases. The environment is often contaminated with a variety of noxious and toxic gases including carbon monoxide, methane, sulphur dioxide, hydrogen sulfide and a broad variety of organic vapors. Some of these are widely prevalent in the environment, particularly in urban areas, and others tend to be pronounced in homes, offices, or other confined spaces due to activities within those spaces. Noxious or toxic materials may be produced from tobacco smoking, cooking, open fireplaces, faulty appliances, or a variety of other normal activities. Some of these are merely unpleasant because of odors while others such as carbon monoxide may be dangerous. Because these pollutants are so prevalent in the air and are found in most locations, contact with them is inevitable. Typically, pollutants cause general discomfort to many people, and can be particularly troublesome to individuals that suffer from emphysema, asthma, and hay fever and like allergies. It has also been found, for example, that a high proportion of homes have unsuspected carbon monoxide concentrations which contribute to vague disorders such as lassitude and headaches at concentrations far below levels that produce overt symptoms of toxicity. Hence, apparatus and methods for removing air pollutants from the air and/or sensing the presence of pollutants have wide spread economic and therapeutic appeal.
Air purifiers are generally known and exist. A typical air purifier includes a housing having a chamber mounting an ultra-violet (UV) lamp. Air is drawn into the bottom of the housing and passes through the chamber where it is exposed to UV radiation emitted from the lamp, which denatures organic proteinous particles, e.g., exterminates microorganisms, that are carried in the air. The air is then discharged from the housing top to the external environment. One prior art air purifier is shown and described in U.S. Pat. No. 4,210,429 of Golstein. The Golstein air purifier employs a UV lamp, which is mounted in a germicidal chamber to exterminate microorganisms that are carried in the incoming flow of air. A charcoal filter is seated above the germicidal chamber and removes odors from the UV radiation exposed air.
Another prior art air purifier is disclosed in U.S. Pat. No. 4,621,195 of Larsson. Larsson also describes an apparatus for destroying microorganisms by irradiation with UV light emitted by a UV lamp supported in an irradiation chamber. The irradiation chamber is segregated into a set of minor chambers by a number of partition walls. The partition walls have formed therein air-flow openings that are oppositely located relative to the openings formed in the adjacent partitions. This alternating arrangement of air-flow openings maximizes the amount of time the air remains in the irradiation chamber in order to maximize the amount of microorganisms destroyed.
Photocatalytic systems such as the one disclosed in U.S. Pat. No. 5,835,840 to Goswami also seek to improve indoor air quality. In the Goswami system, a reactor is provided in which UV lamps are installed such that surfaces coated with a semiconductor catalyst (e.g., TiO2) are exposed to UV radiation as air passes over the surfaces. The combination of the absorption of the UV light photons by the catalyst in the presence of water molecules in the air leads to the creation of hydroxyl radicals, which, in turn, cause the destruction of chemical and microbiological contaminants in the air.
There still exists, however, a need in the art for improved air purifiers that can exterminate microorganisms in the air, as well as reduce or eliminate odors. In particular a need exits for a compact, inexpensive air purifier that is relatively easy to manufacture and that efficiently exterminates microorganisms while reducing odor emissions would represent a major improvement in the art.
The present invention pertains to an air purifier and methods for purifying air by employing ultraviolet radiation with differing energy intensity maxima. Specifically, the air purifier includes an ultraviolet (UV) generating system of one or more radiation sources, the system defining distinct radiating regions that are optically isolated from each other. The air purifier can treat air with various combinations of ozone-producing radiation, cell wall-destroying germicidal radiation and antimicrobial radiation, which may be emitted from any of the radiating regions of the radiation system.
The air purifier of the present invention includes a housing having an irradiation chamber, an air inlet for introducing air into the irradiation chamber, and at least one radiation source disposed within the irradiation chamber. The radiation source or sources are generally one or more lamps, each of which is capable of producing one or more predetermined bands of UV radiation in the range of about 160 nm to about 360 nm.
In one embodiment of the present invention, a single radiation source with at least two distinct radiating or radiation regions is provided in the air purifier. At least one of these radiating regions emits a wavelength between about 160 nm and about 200 nm that is effective to ionize oxygen in the air being treated into ozone, while at least one distinct radiation region will emit a wavelength between about 230 nm and about 280 nm that is effective to destroy the cell walls of active ingredients such as spores and fungi in the air being treated. Treatment of air by both of these radiation regions of the radiation source results in the production of free radical oxygen atoms that, in turn, convert carbon monoxide in the air being treated into carbon dioxide, and which also help reduce the toxicity of volatile organic compounds contained in the air being treated by oxidizing the volatile organic compounds.
In another embodiment of the present invention, a plurality of radiation sources are provided in the air purifier. In this embodiment, like in the single radiation source embodiment, each radiation source can be divided into at least two radiating regions, one of which generates a first energy maximum of ozone-producing radiation and a second, separate energy maximum of germicidal radiation and, optionally, a third separate energy maximum of radiation each as described above with respect to the single radiation source embodiment of the present invention.
In either embodiment, the radiation source may have more than two radiating regions, wherein the additional radiating regions may produce either an additional wavelength between about 160 nm and about 200 nm that is effective to ionize oxygen in the air being treated into ozone, or an additional wavelength between about 230 nm and about 280 nm that is effective to destroy the cell walls of active ingredients such as spores and fungi in the air being treated, or a wavelength of between about 330 and about 360 nm that is effective to reduce the toxicity of volatile organic compounds by oxidizing the volatile organic compounds.
Alternatively, the radiation sources can each be a dedicated source, primarily emitting radiation within a single radiation band with a single energy maximum.
Generally, in each embodiment, the radiation regions will have lengths with respect to each other that approximately correspond to their wavelength relationships, such that the radiation region which produces the longest wavelength will have the largest region length. Likewise, the radiation region which produces the shortest wavelength will generally have the smallest region length.
In the above embodiments, the air purifier further includes an air inlet and an air outlet also formed in the housing for collecting and discharging air, respectively. Moreover, each radiation region of each radiation source is preferably optically isolated from each of the other radiation regions of all of the radiation sources such that each radiation region is prevented from producing radiation that may interact with or xe2x80x9cseexe2x80x9d radiation from any of the other radiation regions of any of the radiation source(s). This optical isolation is effected by the placement of structural optical isolator such as baffles or barriers or a combination thereof in predetermined locations with respect to the radiating regions of the radiation sources.
Also, a predetermined quantity of the inside surface of the air purifier and/or the surfaces of the optical isolator can be made of one or more elements or compounds such as aluminum, and/or coated with one or more elements or compounds such as titanium dioxide in order to aid the reactions caused by the interactions between the wavelengths produced from the radiating regions and air pollutants, microorganisms and other airborne targets of the air purifier.
According to the invention, a first energy maximum occurs at a first relative maximum of the total radiation source energy output that is in the range between about 160 nm and about 200 nm and represents radiation that is effective to ionize oxygen in the air being treated into ozone. A second energy maximum occurs at a second relative maximum of the total radiation source energy output that is in the range between about 230 nm and about 280 nm and that is effective to destroy the cell walls of active ingredients such as spores and fungi in the air being treated. The invention also allows for a third energy maximum of the total radiation source energy output to occur in the range between about 330 nm and 360 nm that is effective to reduce the toxicity of volatile organic compounds. These energy maxima, alone and in concert, act to convert portions of air treated in the air purifier to free radical oxygen ions that, in turn, help convert carbon monoxide in the air being treated into carbon dioxide, as well as help reduce the toxicity of volatile organic compounds in the air being treated by oxidizing the volatile organic compounds.
According to further aspects of the invention, the air purifier further includes a heater mounted within the housing that generates heat, a cooling element mounted within the housing for generating and providing to the external environment cool air, and a filter element, mounted within the purifier, for filtering the air.
According to another embodiment of the invention, the air purifier includes a housing element having an irradiation chamber, an air inlet for allowing air to enter into the housing, an air outlet for allowing air to exit the housing, and an air passage element for introducing air into the irradiation chamber and for moving air-out of the chamber.
The present invention further encompasses a system for purifying air. The system includes a housing element having an air inlet, an air outlet, and an irradiation chamber, an air introduction element that introduces air into the irradiation chamber, and at least one radiation source, mounted within the irradiation chamber, that generates UV radiation having first and second energy maxima within a pair of wavelength intervals. The system further includes a power supply element that supplies power to the air introduction element and the lamp element.
The system can further include a timer element, mounted on the housing, for allowing a user to select a time period in which power is supplied to the lamp. The system can further include a heater, a cooling element, and a filter element, all mounted within the housing.
According to other aspects of the air purifying system, the air introduction means is a blower and the power supply element includes a ballast.
The method of the present invention includes providing a housing having an air inlet and an irradiation chamber, and providing at least one radiation source within the chamber wherein the source or sources are capable of generating or producing a band or spectrum of UV radiation with the following energy maxima in each of its radiation regions: a first energy maximum within a first wavelength band or spectrum of ozone-producing radiation between about 160 nm and about 200 nm, a second energy maximum within a second wavelength band or spectrum of cell wall destroying radiation between about 230 nm and about 280 nm, and an optional third energy maximum of volatile organic compound detoxifying radiation between about 330 nm and about 360 nm. These two or three wavelength intervals cooperate to destroy microorganisms carried in the air and substantially simultaneously deodorize the air.
The method further provides for introducing air into the irradiation chamber through the air inlet, irradiating the inlet air within the chamber, and discharging the irradiated inlet air to an external environment.
The invention further pertains to a gas detection and air purification system that employs an air purifier to remove gas detected by a gas sensor from the external environment. In this embodiment, the purifier can operate in response to an output signal generated by the detector when a selected gas is present in the air.
The air purification and gas removal system of the invention includes a housing having an irradiation chamber, a fan for passing air through the irradiation chamber, and at least one radiation source that is mounted in the irradiation chamber for irradiating the air passing therethrough. The air preferably resides in the irradiation chamber for a time sufficient to purify the air.
According to one aspect, the system further includes a gas detection element, associated with the housing, for detecting the presence of one or more gases in the air. According to one practice of the invention, the gas detection element generates a gas output signal indicative of the presence of the gas in the air. The gas detection element employed in the present invention can detect the presence of most harmful organic gases, such as carbon oxides, benzene, methane, formaldehyde, sulfur dioxide, oxygen, hydrogen, hydrogen sulfide, NOx, ozone and aerosols, and other harmful and/or toxic vapors including organic vapors.
According to another aspect, the system further includes a power element for selectively supplying power to the housing, and thus to the lamp, in response to the gas output signal. The power element is preferably in electrical communication with the at least one radiation source and the gas detection element.
The invention will next be described in connection with certain preferred embodiments. However, it should be clear that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. For example, various housings having differing shapes can be employed to house the lamp.
The foregoing and other objects, features, aspects and advantages of the invention will be apparent from the following description and apparent from the accompanying drawings, in which like reference characters refer to the same parts throughout the embodiments and different views. The drawings illustrate principles of the invention and, although not to scale, show relative dimensions.
FIG. 1 is a plan view of a first embodiment of an air purifier according to the invention;
FIG. 1A is an enlarged view of section 1A of the air purifier of FIG. 1;
FIG. 2 graphically illustrates the relative maximum wavelengths of radiation produced by the radiation source housed within the air purifier of FIG. 1 according to a preferred embodiment of the invention;
FIG. 3 is a plan view of an air purifier according to a second embodiment of the invention;
FIG. 4 is a plan view of the air purifier of FIG. 2 which mounts a heat exchanger;
FIG. 5 is a plan view of the air purifier of FIG. 3 which mounts an air conditioning condenser;
FIG. 6 is a plan view of a third embodiment of an air purifier according to the invention;
FIG. 7 is a plan view of an air purifying and gas detection system in accordance with the present invention;
FIG. 8 is a plan view of a second embodiment of the air purifying and gas detection system of FIG. 7;
FIG. 9 is a plan view of another embodiment of an air purifying device according to the invention;
FIG. 10 is a plan view of a third embodiment of the air purifying device according to the invention; and
FIG. 11 is a plan view of an alternate embodiment of the radiation source of both the air purifier of FIGS. 1 and 3-6 and the air purifying device of FIG. 7.